1. Field of the Invention
This invention relates to an ink-jet recording method and, more particularly, to an ink-jet recording method for producing vivid recording images with improved resolution and contrast.
2. Description of the Prior Art
In general, ink-jet recording involves the projection of droplets of recording liquid, or "ink" using various techniques such as electrostatic attraction, utilizing pizoelectric elements to cause a mechanical displacement that projects a quantity of ink, and heating a quantity of ink to form a bubble, wherein the pressure created thereby is utilized to project a droplet of ink. The droplets of ink attach to a recording material such as paper, thus forming the desired recording. Ink-jet recording is worthy of attention because, among other things, it is capable of performing high-speed and multi-color printing without generating a great deal of noise.
A material comprising a liquid medium and a water-soluble dye, as the recording agent, is typically used as an ink for ink-jet recording.
Water-soluble dyes, preferably acid dyes or direct dyes, may be used as recording agents in consideration of such factors as safety, fade-resistance and general recording characteristics, and a liquid whose chief ingredient is water may be used as the liquid medium, also in view of safety considerations general recording characteristics. A polyhydric alcohol or the like may be added to the liquid medium for preventing blockage of the ink nozzles and for improving droplet ejection stability.
Materials such as ordinary kinds of paper or so-called ink-jet recording paper, having a base on which a porous ink receiving layer is formed, have been used as recording mediums for conventional ink-jet recording techniques. Recently, however, there is a widespread desire further to improve and extend the characteristics of such recording mediums, in view of improvements in the performance of recording apparatuses such as high-speed and multi-color ink-jet recording apparatus.
That is, if recording medium characteristics are to be improved, it is necessary for the ink to be rapidly absorbed by the recording medium so as to provide a dot that covers a given area and has the proper shape and border.
When color ink-jet recording is performed, it is necessary to use a recording medium which enables the dyestuffs which act as the recording agents to display high quality coloring properties and vividness, so as to achieve a high standard of chromaticity.
In addition, images formed by ink-jet recording are required to be highly stable, long lasting and water and light resistant.
Ink jet recording has been improved to some degree by providing a recording medium with a special ink receiving layer.
However, while recording mediums have been developed along these lines, it is now sought to perform image recording with vividness and resolution such as comparable to photographs.
In order to satisfy these requirements, it is necessary to put nearly perfectly round ink dots on the recording surface. To this end, attempts have been made to improve the recording surface of recording mediums used in accordance with the conventional recording methods. But while the amount of distortion in the ink dots on the recording surface can be reduced to some degree, it is not possible to heighten the vividness and resolution beyond a certain point no matter how much the recording surface is improved. Thus, images formed in accordance with the known methods are much inferior to photographic images in terms of vividness and resolution.